Initial documentation for cover templates (#2842)

* Initial documentation for cover templates

* Fix many typos found during review.

* Fix typos and formatting

source/_components/cover.template.markdown

@@ -0,0 +1,77 @@
+---
+layout: page
+title: "Template Cover"
+description: "Instructions how to integrate Template covers into Home Assistant."
+date: 2017-06-19 20:32
+sidebar: true
+comments: false
+sharing: true
+footer: true
+ha_category: Cover
+ha_release: 0.48
+ha_iot_class: "Local Push"
+logo: home-assistant.png
+---
+
+The `template` platform can create covers that combine components and provides the ability to run scripts or invoke services for each of the open, close, stop, position, and tilt commands of a cover. 
+
+To enable Template covers in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+cover:
+  - platform: template
+    covers:
+      garage_door:
+        friendly_name: "Garage Door"
+        value_template: "{% raw %}{{is_state('sensor.garage_door > 0'}}{% endraw %}"
+        open_cover:
+          service: script.open_garage_door
+        close_cover:
+          service: script.close_garage_door
+        stop_cover:
+          service: script.stop_garage_door
+```
+
+Configuration variables:
+
+- **covers** array (*Required*): List of your coverss.
+  - **open_cover** (*Required*): Defines an [action](/getting-started/automation/) to run when the cover is opened.
+  - **close_cover** (*Required*): Defines an [action](/getting-started/automation/) to run when the cover is closed.
+  - **stop_cover** (*Required*): Defines an [action](/getting-started/automation/) to run when the cover is stopped.
+  - **set_cover_position** (*Optional*): Defines an [action](/getting-started/automation/) to run when the cover is set to a specific value (between 0 and 100).
+  - **set_cover_tilt_position** (*Optional*): Defines an [action](/getting-started/automation/) to run when the cover tilt is set to a specific value (between 0 and 100).
+  - **friendly_name** (*Optional*): Name to use in the frontend.
+  - **value_template** (*Optional*): Defines a [template](/topics/templating/) to get the state of the cover. Valid values are open/true or closed/false. Either `value_template` or `position_template` must be specified.
+  - **position_template** (*Optional*): Defines a [template](/topics/templating/) to get the state of the cover. Legal values are numbers between 0 (closed) and 100 (open). Either `value_template` or `position_template` must be specified.
+  - **icon_template** (*Optional*): Defines a [template](/topics/templating/) to specify which icon to use. Either `value_template` or `position_template` must be specified.
+  - **entity_id** (*Optional*): Add a list of entity IDs so the switch only reacts to state changes of these entities. This will reduce the number of times the cover will try to update it's state.
+
+
+## {% linkable_title Examples %}
+
+In this section you will find some real life examples of how to use this cover.
+
+### {% linkable_title Garage Door %}
+
+This example converts a garage door with a controllable switch and position sensor into a cover.
+
+```yaml
+cover:
+  - platform: template
+    covers:
+      garage_door:
+        friendly_name: 'Garage Door'
+        value_template: "{% raw %}{{ sensor.garage_door }}{% endraw %}"
+        open_cover:
+          service: switch.turn_on
+          entity_is: switch.garage_door
+        close_cover:
+          service: switch.turn_off
+          entity_is: switch.garage_door
+        stop_cover:
+          service: switch.turn_on
+          entity_is: switch.garage_door
+        icon_template: "{% raw %}{% if not is_state('sensor.garage_door', 'on') %}mdi:garage-open{% else %}mdi:garage{% endif %}{% endraw %}"
+
+```